Bioenergetics of Exercise Reading: Essentials of S&C 73-91 Christopher T. Ray, Ph.D., ATC, CSCS.

Bioenergetics of Bioenergetics of ExerciseExercise

Reading: Essentials of S&C Reading: Essentials of S&C 73-9173-91

Christopher T. Ray, Ph.D., ATC, CSCSChristopher T. Ray, Ph.D., ATC, CSCS

Extra Credit Extra Credit Opportunity #1Opportunity #1

HousekeepingHousekeeping

ScheduleSchedule– Assessments with partnersAssessments with partners

Next Wed & FriNext Wed & Fri– Sign in 9:00-9:05; Assessments 9:00–9:35 Sign in 9:00-9:05; Assessments 9:00–9:35 Plan Plan

accordinglyaccordingly

Equipment = Calipers, S&R Box, VERTEC, Tape Equipment = Calipers, S&R Box, VERTEC, Tape Measurer, cones, masking tape, courts, indoor Measurer, cones, masking tape, courts, indoor track & weight room. track & weight room.

Questions?

What?What?

What does Exercise Rx mean to What does Exercise Rx mean to you?you?

What do mean when I say “Be What do mean when I say “Be Evidence Based”Evidence Based”

Why Did Usain Bolt not Run the 400 meters? WR 100 meters = 9.69 WR 200 meters = 19.30

WR 400 meters = 43.18; 43.75 = Gold

*45.29

Table 5.3 Effect of Event Duration on Primary Energy System Used

Duration Intensity Primary energyof event of event system(s)

0-6 s Very intense Phosphagen

6-30 s Intense Phosphagen and fastglycolysis

30 s-2 min Heavy Fast glycolysis

2-3 min Moderate Fast glycolysis andoxidative system

> 3 min Light Oxidative system

PracticePractice

SportSport AssessmentAssessment Training Regime (Int., Duration, Rest)Training Regime (Int., Duration, Rest)

Calculations

200 meter PR = 20; Training 75% - 90%; Recovery = 1:3-1:5– 20 X 1.10 = 22 X 5 = 110 sec.– 20 X 1.25 = 25 X 3 = 75 sec.

“Wolff’s Law”

The body adapts to the stress placed upon it.

law according to which biologic systems such as hard and soft tissues become distorted in direct correlation to the amount of stress imposed upon them.

Bio-energetics is dynamic

1.1. The Principle of IndividualityThe Principle of Individuality2.2. The Principle of SpecificityThe Principle of Specificity3.3. The Principle of Progressive OverloadThe Principle of Progressive Overload4.4. The Principle of Hard / EasyThe Principle of Hard / Easy5.5. The Principle of PeriodizationThe Principle of Periodization6.6. The Principle of DisuseThe Principle of Disuse

Basic Training PrinciplesBasic Training Principles


1. The Principle of Individuality1. The Principle of IndividualityDifferent people respond to the same training in different Different people respond to the same training in different ways. Heredity plays a major role in determining how ways. Heredity plays a major role in determining how quickly and to what degree the athlete adapts to a training quickly and to what degree the athlete adapts to a training program.program.

For these reasons any training program For these reasons any training program “must take into “must take into account the specific needs and abilities of the individuals account the specific needs and abilities of the individuals for whom it is designed.”for whom it is designed.”


2. The Principle of Specificity2. The Principle of SpecificityTo maximize the benefits, training must be specifically To maximize the benefits, training must be specifically matched to the type of activity the athlete use to be matched to the type of activity the athlete use to be engaged in. (engaged in. (endurance vs strength and power trainingendurance vs strength and power training).).By this principle the training program must stress the By this principle the training program must stress the physiological systems that are critical for optimal athlete’s physiological systems that are critical for optimal athlete’s performance, in order to achieve performance, in order to achieve specific adaptations for specific adaptations for specific sports.specific sports.

3. The Principle of Progressive Overload3. The Principle of Progressive OverloadOverload Overload andand Progressive Training Progressive Training are the foundation of are the foundation of all training programs. all training programs. A well-designed Training Program must involve working A well-designed Training Program must involve working the muscles, respiratory and cardiovascular systems the muscles, respiratory and cardiovascular systems harder than normal (harder than normal (overloadoverload); as the body adapts, ); as the body adapts, Training progresses to a higher work level (Training progresses to a higher work level (progressive progressive trainingtraining))


4. The Principle of Hard / Soft4. The Principle of Hard / SoftBill Bowerman (former U.S. Olympic track coach and Bill Bowerman (former U.S. Olympic track coach and founder of NIKE) developed a training strategy for his founder of NIKE) developed a training strategy for his distance running that became known as distance running that became known as ‘ The principle of ‘ The principle of hard / soft’.hard / soft’.

According to this principle, one or two days of hard According to this principle, one or two days of hard training should be followed by one day of soft training, training should be followed by one day of soft training, allowing the fully recover of body and mind and prevent allowing the fully recover of body and mind and prevent the athlete’s overtraining.the athlete’s overtraining.


5. The Principle of Periodization5. The Principle of PeriodizationPeriodization is the gradual cycling of Periodization is the gradual cycling of

specificityspecificity, , intensity intensity and and volume volume of training to of training to achieve achieve peak levelspeak levels of fitnessof fitness for competition. for competition.


6. The Principle of Disuse6. The Principle of Disuse“ “ Use it or loose it”Use it or loose it”

According to this principle, training benefits are lost if According to this principle, training benefits are lost if training is either discontinued or reduced too abruptly.training is either discontinued or reduced too abruptly.

To avoid this, all training programs must include a To avoid this, all training programs must include a maintenance programmaintenance program..


Opportunity to get Opportunity to get back on my good side back on my good side #1#1 Pick a sportPick a sport

– What are the componentsWhat are the components– Where does it fit on the Where does it fit on the

bioenergetics spectrum?bioenergetics spectrum?

How would you train athletes in How would you train athletes in this sport?this sport?

How would you Assess them?How would you Assess them?

IntroductionIntroduction

-- Energy Energy Ability to do work Ability to do work

– Bioenergetics Bioenergetics Flow of energy in a biological system Flow of energy in a biological system

– Catabolism Catabolism Breakdown of larger molecules into Breakdown of larger molecules into

smaller molecules (glucose to pyruvate)smaller molecules (glucose to pyruvate)

– Anabolism Anabolism Synthesis of larger molecules from smaller Synthesis of larger molecules from smaller

molecules (polypeptide from AA residuals)molecules (polypeptide from AA residuals)


– Exergonic reactions Exergonic reactions Energy-releasing reaction; generally catabolic Energy-releasing reaction; generally catabolic

reaction reaction Ex. Blood glucose during catabolism = release of Ex. Blood glucose during catabolism = release of

energyenergy

– Endergonic reactions Endergonic reactions Energy-consuming reaction; generally anabolic Energy-consuming reaction; generally anabolic

reaction reaction Ex. Protein synthesis Ex. Protein synthesis

– Metabolism Metabolism Total of all the catabolic/exergonic and Total of all the catabolic/exergonic and

anabolic/endergonic reactions in a systemanabolic/endergonic reactions in a system


– ATP ATP Adenosine triphosphate; intermediate Adenosine triphosphate; intermediate

molecule that allows the transfer of molecule that allows the transfer of energy from exergonic to endergonic energy from exergonic to endergonic reactions reactions

– Smallest usable form of energy Smallest usable form of energy

Biological Energy Biological Energy Systems Systems

– Three energy systems used to Three energy systems used to replenish ATP replenish ATP

Phosphagen Phosphagen – Occurs in the sarcoplasm Occurs in the sarcoplasm – An anaerobic energy system An anaerobic energy system

Glycolytic Glycolytic – Occurs in the sarcoplasm Occurs in the sarcoplasm – An anaerobic energy system An anaerobic energy system

Oxidative Oxidative – Occurs in the mitochondria Occurs in the mitochondria – An aerobic energy systemAn aerobic energy system

Biological Energy Biological Energy SystemsSystems Phosphagen systemPhosphagen system (anaerobic), occurs (anaerobic), occurs

without oxygen.without oxygen. GlycolysisGlycolysis ( (Fast & SlowFast & Slow) is the ) is the

breakdown of carbohydrates, either breakdown of carbohydrates, either glycogen stored in the muscle or glycogen stored in the muscle or delivered in the blood to produce ATP.delivered in the blood to produce ATP.

Oxidative systemOxidative system is the primary source is the primary source of ATP at rest and low-intensity, it uses of ATP at rest and low-intensity, it uses primarily carbohydrates and fats as primarily carbohydrates and fats as substrates.substrates.All three energy systems are active at a given time; the extent to

which each is used depends on the intensity of the activity and its duration.

Biological Energy Biological Energy SystemsSystems All energy systems are active at All energy systems are active at

any given time any given time – The extent of their contribution: The extent of their contribution:

Primary Primary – Intensity, power output, work rate Intensity, power output, work rate

Secondary Secondary – DurationDuration

Phosphagen System Phosphagen System

– Primary functions Primary functions Provide ATP for high intensity activitiesProvide ATP for high intensity activities

(e.g., sprinting, weight training) (e.g., sprinting, weight training) For 0-6 seconds up to 20-30 seconds of For 0-6 seconds up to 20-30 seconds of

activity activity Active at the start of all exercise Active at the start of all exercise

– Regardless of intensity! Regardless of intensity!

Summary of Summary of Phosphagen System Phosphagen System

– Summary: Summary: Rapid ATP resynthesis rate Rapid ATP resynthesis rate Efficient system (due to the few number Efficient system (due to the few number

of involved reactions) of involved reactions) – Creatine kinase reaction Creatine kinase reaction – Myokinase reaction Myokinase reaction

BUT a low capacity of total ATP BUT a low capacity of total ATP producedproduced

Glycolytic System Glycolytic System

– Primary functions Primary functions Carbohydrate (CHO) (i.e., blood glucose Carbohydrate (CHO) (i.e., blood glucose

and muscle glycogen) break down to and muscle glycogen) break down to produce ATPproduce ATPin the sarcoplasm of a muscle cell in the sarcoplasm of a muscle cell

– Provides energy primarily for moderate to Provides energy primarily for moderate to high intensity activities high intensity activities

– For 30 seconds up to 2-3 minutes of activity For 30 seconds up to 2-3 minutes of activity – Hypoxic (anaerobic) cellular environmentHypoxic (anaerobic) cellular environment

Glycolytic System Glycolytic System

Fate of pyruvate Fate of pyruvate – High rate of energy demand High rate of energy demand – Insufficient O2 present Insufficient O2 present – Fast glycolysis (pyruvate to lactate) Fast glycolysis (pyruvate to lactate) – Example: 1200 meter sprint run Example: 1200 meter sprint run

Low rate of energy demand Low rate of energy demand – Sufficient O2 present Sufficient O2 present – Slow glycolysis (pyruvate [with NADH] is Slow glycolysis (pyruvate [with NADH] is

sent to the Krebs Cycle in the mitochondria) sent to the Krebs Cycle in the mitochondria) – Example: 30 minute stair climbing workoutExample: 30 minute stair climbing workout

Summary of Fast Summary of Fast GlycolysisGlycolysis

Fast glycolysis occurs during reduced oxygen Fast glycolysis occurs during reduced oxygen availability and the end product is lactic acid.availability and the end product is lactic acid.

Lactic acid accumulation in tissue is the result of Lactic acid accumulation in tissue is the result of an imbalance of production & utilization.an imbalance of production & utilization.

As lactic acid accumulates, there is an increase in As lactic acid accumulates, there is an increase in the concentration of Hthe concentration of H++ ++ ions.ions.

HH++ ++ ions inhibit glycolytic reactions.ions inhibit glycolytic reactions. HH++++ ions interfere with E-C coupling by inhibiting Ca ions interfere with E-C coupling by inhibiting Ca

from binding with troponin.from binding with troponin.

The decrease in pH also inhibits enzymaticThe decrease in pH also inhibits enzymatic activity.activity.

Lactic Acid and LactateLactic Acid and Lactate Lactic acid is converted to its salt, lactate, by Lactic acid is converted to its salt, lactate, by

buffering systems in the muscle and blood.buffering systems in the muscle and blood. Lactate is not fatigue producing, it is often used as Lactate is not fatigue producing, it is often used as

an energy system in Type I and cardiac muscle.an energy system in Type I and cardiac muscle. Lactate is used in gluconeogensis, the formation of Lactate is used in gluconeogensis, the formation of

glucose from lactate and non-carbohydrate sources glucose from lactate and non-carbohydrate sources during extended exercise and recovery.during extended exercise and recovery.

Concentrations of lactate in blood and muscle: Concentrations of lactate in blood and muscle: – At rest, 0.5 – 2.2 mmol/LAt rest, 0.5 – 2.2 mmol/L– At high intensity exercise 20 – 25 mmol/LAt high intensity exercise 20 – 25 mmol/L

Peak blood lactate concentrations occur Peak blood lactate concentrations occur approximately 5 minutes after the cessation of approximately 5 minutes after the cessation of exercise.exercise.

Blood lactate accumulation is greater following high-Blood lactate accumulation is greater following high-intensity intermittent exercise, than lower intensity intensity intermittent exercise, than lower intensity continuous exercise.continuous exercise.

Oxidative System Oxidative System

- Primary function - Primary function – Provide ATP for low intensity activities (e.g.,Provide ATP for low intensity activities (e.g.,

long distance running, cycling, swimming) long distance running, cycling, swimming) – For longer than 3 minutes of activity For longer than 3 minutes of activity

– Substrates Substrates CHO CHO Fats Fats Proteins Proteins

– Reactions occur in the mitochondria Reactions occur in the mitochondria ““Power house” of the muscle cellPower house” of the muscle cell

Oxidative (Aerobic) System

Requires molecular oxygen

Uses primarily carbohydrates and fats as substrates

Provides ATP at rest and during low-intensity activities

At rest, 70% of ATP is from fats & 30% carbs.

As exercise intensity increases there is a shift from fats to carbohydrates as substrates.

At high intensity, almost 100% of ATP is from carbs.

During prolonged, submaximal steady state work, there is a gradual from carbs back to fats & proteins.

Summary of Oxidative Summary of Oxidative System System

– Adaptations to training Adaptations to training Increased muscle mitochondrial content Increased muscle mitochondrial content

More effective sparing of CHO for use by More effective sparing of CHO for use by

the central nervous system the central nervous system Blunted drop in intracellular pH during a Blunted drop in intracellular pH during a

long-term aerobic endurance eventlong-term aerobic endurance event

Substrate Depletion Substrate Depletion and Repletion and Repletion

– Energy substrates used to produce Energy substrates used to produce ATP ATP

– Phosphagen Phosphagen – Glycogen Glycogen – Glucose Glucose – Lactate Lactate – Free fatty acids Free fatty acids – Amino acids Amino acids


– Phosphagen and ATP Phosphagen and ATP Depletion Depletion

– Creatine phosphate (CP) stores can Creatine phosphate (CP) stores can decrease 50-70% in the first 5-30 seconds decrease 50-70% in the first 5-30 seconds

– CP stores are virtually eliminated as a result CP stores are virtually eliminated as a result of high intensity exercise of high intensity exercise

– ATP stores do not decrease more than 60% ATP stores do not decrease more than 60% even with very intense exerciseeven with very intense exercise


– Phosphagen and ATP Phosphagen and ATP Repletion Repletion

– Post-exercise resynthesis of ATP can occur Post-exercise resynthesis of ATP can occur withinwithin3-5 minutes 3-5 minutes

– Post-exercise resynthesis of CP may require Post-exercise resynthesis of CP may require up toup to8 minutes 8 minutes

– Most post-exercise CP resynthesis is Most post-exercise CP resynthesis is accomplished through oxidative energy accomplished through oxidative energy pathwayspathways

Oxidative Oxidative system yields system yields 38 ATP from 38 ATP from 1 glucose 1 glucose molecule.molecule.

Energy Production and Energy Production and Capacity Capacity

– Rate and capacity of the three Rate and capacity of the three energy systems to supply ATP energy systems to supply ATP Inverse relationship Inverse relationship Rate (how fast ATP can be created) Rate (how fast ATP can be created) Capacity (how much ATP can be Capacity (how much ATP can be

created)created)

Table 5.4 Rankings of Rate and Capacity of ATP Production

System Rate of ATP Capacity of ATPproduction production

Phosphagen 1 5

Fast glycolysis 2 4

Slow glycolysis 3 3

Oxidation of carbs 4 2

Oxidation of fats and proteins 5 1

1 = fastest/greatest; 5 = slowest/least

Energy Production and Energy Production and Capacity Capacity

The use of appropriate exercise intensities and rest

intervals allows for the “selection” of specific energy

systems during training and results in more efficient and

productive regimens for specific athletic events with

various metabolic demands.

Substrate Depletion Substrate Depletion and Repletionand Repletion ATP and creatine phosphate, ATP and creatine phosphate,

glucose, glycogen, lactate, FFA glucose, glycogen, lactate, FFA and amino acids can be and amino acids can be selectively depleted.selectively depleted.

Phosphagen Depletion Phosphagen Depletion & Repletion& Repletion Phosphagens are more rapidly depleted with high Phosphagens are more rapidly depleted with high

intensity exercise than aerobic exercise.intensity exercise than aerobic exercise. Creatine Phosphate decreases 50-70% during high Creatine Phosphate decreases 50-70% during high

intensity exercise and can be almost eliminated by intensity exercise and can be almost eliminated by exercise to exhaustionexercise to exhaustion

Muscle ATP concentrations do not decrease by more Muscle ATP concentrations do not decrease by more than 60% of initial value even during intense exercise.than 60% of initial value even during intense exercise.

Intramuscular ATP is spared by the depletion of creatine Intramuscular ATP is spared by the depletion of creatine phosphate from the myosine kinase reaction.phosphate from the myosine kinase reaction.

Post exercise repletion of phosphagen with:Post exercise repletion of phosphagen with:– Resynthesis of ATP in 3 – 5 minResynthesis of ATP in 3 – 5 min– Complete creatine phosphate resynthesis in 8 minComplete creatine phosphate resynthesis in 8 min

Resistance training can result in an increase in the Resistance training can result in an increase in the resting concentration of phosphagens.resting concentration of phosphagens.

Glycogen Depletion & Glycogen Depletion & RepletionRepletion Limited stores of glycogen are available for exercise, Limited stores of glycogen are available for exercise,

approx. 300-400 g in total body muscle and 70-100 g in approx. 300-400 g in total body muscle and 70-100 g in the liver.the liver.

Anaerobic training can increase glycogen stores.Anaerobic training can increase glycogen stores. Muscle glycogen is more important than liver during Muscle glycogen is more important than liver during

moderate – intense exercise.moderate – intense exercise. Liver glycogen is more important in low intensity exercise Liver glycogen is more important in low intensity exercise

and its contribution increases with duration.and its contribution increases with duration. Repletion of muscle glycogen during recovery is related to Repletion of muscle glycogen during recovery is related to

post exercise carbohydrate consumption.post exercise carbohydrate consumption. Repletion is optimal if 0.7 – 3.0 g of carbs/kg is ingested Repletion is optimal if 0.7 – 3.0 g of carbs/kg is ingested

every 2 hrs.every 2 hrs. Muscle glycogen may be completely replenished within Muscle glycogen may be completely replenished within

24 hrs with sufficient carbs in diet.24 hrs with sufficient carbs in diet.

Glycogen depletion can be a limiting factor both Glycogen depletion can be a limiting factor both for:for:– Long duration, low intensity exerciseLong duration, low intensity exercise– Repeated very high – intensity exerciseRepeated very high – intensity exercise

Lactic acid and tissue HLactic acid and tissue H++++ ion concentration can be ion concentration can be limiting factors for resistance training, sprinting and limiting factors for resistance training, sprinting and other anaerobic activities.other anaerobic activities.

Low-Intensity, Steady-State Exercise MetabolismLow-Intensity, Steady-State Exercise Metabolism

EPOC = Excess postexercise oxygen uptake

At the start of At the start of exercise, some of exercise, some of the energy is the energy is provided by provided by anaerobic anaerobic metabolism.metabolism.

The anaerobic The anaerobic contribution to the contribution to the total energy cost is total energy cost is termed termed Oxygen Oxygen Deficit.Deficit.

Post-exercise Post-exercise oxygen uptake oxygen uptake remains elevated remains elevated according to according to intensity and intensity and duration and is duration and is termed termed Oxygen Oxygen Debt. Debt.

High-Intensity, Non-Steady-State Exercise MetabolismHigh-Intensity, Non-Steady-State Exercise Metabolism

Bioenergetics of Exercise Reading: Essentials of S&C 73-91 Christopher T. Ray, Ph.D., ATC, CSCS.

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Transcript of Bioenergetics of Exercise Reading: Essentials of S&C 73-91 Christopher T. Ray, Ph.D., ATC, CSCS.